Load both XP version and other version on same flash drive.

Still downloading XP version after saving regular version on USB flash drive. Am anticipating problems with the bootable XP version being on the same flash drive as the regular version. I put the regular version in a separate folder but am wondering if the XP version will auto boot if I try to use it on a nonXP computer. ???? Also getting notified by Norton Security is not allowing the XP version to finish, it removes the file, I have disabled Norton temporarily and am trying again..